1. Field of the Invention
This invention relates to a labelling machine which is controlled by a digital data processing system. More particularly, it relates to such a system in which mechanical camming mechanisms and similar components of a conventional labelling machine are replaced by electronic controls embodied in a digital data processing system connected to control tuning, feed and related operations of a labelling machine of the type which is able to apply labels of various sizes to packaging containers of various sizes.
2. Description of the Prior Art
In conventional machines used to apply different size labels to different size cans, glass bottles, boxes or other packaging containers, timing marks, cams, gears and similar interconnected mechanical elements are employed to assure that the containers and labels are supplied to the machine in an orderly fashion and syncronously with respect to each other so that a single label is uniformly placed in a desired location on the container. Some control functions of labelling machines have also been implemented with digital circuits, including microprocessors.
It is also known in the prior art to replace various mechanical timing devices in complex machines, such as internal combusion engines with digital electronics. Many such timing mechanisms have been replaced in automobile engines through the use of digital data processing circuits embodied in microprocessor integrated circuits, in combination with various electronic and electromechanical sensing circuits.
However, labelling machines are very complex devices with many unique problems. Hitherto, it has not been known in the art to replace the mechanical control systems for main drive shafts used in labelling machines with digital data processing and electrical sensing circuits. Examples of such labelling machines are described, for example, in the following commonly assigned issued patents and pending patent applications: U.S. Pat. Nos. 3,765,991; 4,108,709; 4,181,555; 4,188,843; 4,242,167; 4,336,095; and application Ser. No. 783,285.